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'(No Model.)

' G. T. MOORE.

,SASH CHAIN. V N0. 357,620. Patented F eb. 15, 1887.

WITNESSES v 1N V'EJV'TOR u. Pnzns, Pholn-Lithognphsr. walhinglun. D cv UNITED STATES PATENT OFFICE.

GEoEGE T. MOORE, OF NEW YORK, N. Y.

SASH-Cl-IAIN.

SPECIFICATION forming part ofibetters Patent No. 357,620, dated February 15,1887.

Application filed November 11, 1886. Serial No. 218,514.

To aZZ whom it may concern.-

Be it known that I,

GEORGE T. MOORE, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Sash Chains and Plumbers Chains, of which the following is a specification, reference being bad therein to the accompanying drawings.

.This invention relates to certain new and useful improvements in chains formed by links out from sheet metal, having special reference to what are known in the trade as sash and plumbers chains;.and the object of the invention is to strengthen that portion of the links which lies between the slots formed in the ends of the links, so as to prevent said portion from breaking when the chain is undergoing extreme tensile strain, the tendency of which is to draw out or flatten the bent portion of the links, and to thus make the bend too acute to withstand breakage.

I11 the accompanying drawings, forming a part of this specification, and on which similar letters of reference indicate the same or corresponding features, Figure 1 represents a plan view of achain composed of several of my improved links. Fig. 2 is an edge view thereof; Fig. 3, a view of a link before it is folded, and Fig. 4 a cross-sectional view of the portion between the slots.

The common way of manufacturing chainlinks of the character to which my improvement relates is by stamping the links from sheet metal by means of a die, the stamp also cutting the slots in the ends of the link-blank. This same method is followed in manufacturing my improved link, so far as concerns the features of it which are now well known.

Referring now to the accompanying drawings, the letter A designates the links stamped from sheet metal, with slots B and an intermediateimperforatedportion,(l. Afterstamping,

(or during the operation of stamping, if the die be so constructed,) the said intermediate por- (No model.)

tion is formed with a depression on one side and a corresponding bulge on the opposite side, forming a groove, and a bead upon the respective sides. A link thus made is bent or foldedover, and then a number of links are strung together to form a chain.

It will be observed that the portion which receives the bend presents, substantially, a semicircle, which is the natural curvature the metal takes in folding the link, and which curvature does not disturb the molecules sufficiently to expose the curved portion to breakage or to cracking on the outer side. When,

however, excessive strain is brought upon the chain, the curved portion without my improved bead tends to draw out or flatten, which action cracks the outside of the bend and causes the link to break. With the bead in the bent portion, however, this flattening action, due to excessive strain, is successfully resisted, and hence the tensile strength of the chain is multiplied many-fold.

' It should be noted that while this improvement confers the benefits named upon the chain, it does not materially increase the cost of manufacture, nor does it involve a greater consumption of material.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A sheetmetal chain link having the central curved portion thereof provided with a depression on one side and a bulge on the other, produced by swaging the metal thereof.

'2. A sheet metal chain-link provided with a slot near each end and with an intermediate imperforated bent portion provided with a depression on one side and a bulge on the other.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE T. MOORE. 

